High Performance Liquid Chromatography (HPLC)

Polyhedron offers liquid chromatography, specifically High Performance Liquid Chromatography (HPLC) with photo diode array detection. HPLC is a form of column chromatography used in analytical chemistry and biochemistry. Basically, an analyte is forced through a stationary phase column in a liquid (the mobile phase) at high pressure, resulting in a decrease in the time the separated parts remain on the stationary phase. The result is narrower peaks in the chromatogram, leading to better sensitivity (taller, narrower peaks are easily distinguishable from noise than broader, shorter peaks) and better resolution (again, one peak is easy to distinguish from another). Polyhedron Laboratories also provides determination of antioxidants and slip additives by ASTM D 5815.

ASTM D 5815-95e1

This test procedure outlines a liquid- chromatographic routine for the separation of some additives currently used in linear low-density polyethylene. These additives are extracted with either isopropanol or isobutanol prior to liquid-chromatographic separation. The ultraviolet absorbance of the compound is calculated; quantitation is done using an internal standard method.